The central hypothesis is that restoring circulating DHEA levels of older people with low levels to more youthful levels will be associated with beneficial changes in body composition. The specific aims are to examine in 65-85 yr-old women and men the effects of 1yr DHEA replacement on: a) fat mass and fat-free mass; b) intra-abdominal fat volume and thigh muscle area by MRI; c) bone mineral density; d) glucose tolerance and insulin response evaluated using an oral glucose tolerance test. The hypothesis is that DHEA replacement will increase fat-free mass and bone mineral density and decrease fat mass. Additional hypotheses are that: 1) The increase in fat-free mass will be due to an increase in muscle mass. 2) The decrease in fat mass will be predominantly in the trunk regions. And 3) The increase in bone mineral density will be due to a decrease in bone resorption and a reduced insulin response to an oral glucose load will occur despite no change in the glucose response, indicating enhanced insulin action. The role of IGF-1 will be examined, as measured from IGF-1 and IGHBP-3, by examining whether these hormones predict changes in the aforementioned variables. The volunteers will be 72 men and 72 women, aged 56-85 yr who are healthy. They will be randomized to receive either a replacement dose of DHEA or placebo. If these results are confirmed, this will suggest the DHEA deficiency and its replacement may play an important role in the prevention of sarcopenia.